Here's the question you clicked on:
kenneyfamily
Write an equation of the sine function with: amplitude = 7 period = 3π phase shift = π vertical shift = -7
So lets think about what these things mean... Are you familiar with amplitude?
OK, Amplitude is how much to 'amplify' the function by.
or you could say, multiply.
If you have 5Sin(x) then its amplitude is 5 (the wave will hit a maximum of 5 and a minimum of -5.
So hopefully that explains amplitude. The period is the length of a wave before it starts repeating itself. The usual period of a sine function is 2Pi as the wave will begin to repeat after that point in time. I.e. period of Sin(x) is 2Pi. Is this making sense so far?
yep, thats right, 7 sin x (for the amplitude part)
\[y(x)=A\sin(\omega t+\phi)+b\] \(A\) is the Amplitude \(\omega\) is the angular frequency \(\frac{\omega}{2\pi}=\)frequency of oscillation \(\tau\) is the period and \(\tau=\frac{2\pi}{\omega}\) \(\phi\) is the phase shift \(b\) is the vertical shift
You are best of taking a look at http://www.intmath.com/trigonometric-graphs/trigo-graph-intro.php. This will explain it properly.